How often must TFN details be updated?

The correct choice emphasizes that TFN (Tax File Number) details should be updated as needed, particularly after any personal changes. This means that any time there is a significant life event, such as a change of address, a change of name due to marriage or divorce, or a change in residency status, individuals are required to inform the relevant authorities to ensure their tax records are accurate and up to date. Keeping these details current is essential to facilitate the proper processing of tax returns and to maintain compliance with tax obligations.

The frequency of updates is not rigidly set, which is why annual updates or updates only upon advisement by the ATO do not accurately reflect the necessary procedure. Additionally, stating that TFN details never need to be updated is misleading, as it overlooks the reality that individual circumstances can change significantly over time. Hence, option B provides the most accurate and practical approach to managing TFN details.